DE102023101201A1 - System and method for operating a vibrating beam - Google Patents

Abstract

A vibratory screed includes a drive unit, a plurality of screed blades, each of the plurality of screed blades being releasably engaged to the drive unit; The screed further includes a drive unit controller operatively coupled to the drive unit, an accumulator operatively coupled to the drive unit controller, and a blade selector operatively coupled to the drive unit controller. The drive unit controller is operable to receive a blade selection from the blade selector, the blade selection indicating a size of a particular screed blade of the plurality of screed blades; retrieve a range of operating speeds associated with sheet selection; and adjusting the operating speed of the screed to correspond to the range of operating speeds associated with blade selection.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to the co-pending provisionals filed on January 18, 2022 U.S. Patent Application No. 63/300,418 , the entire contents of which are hereby incorporated by reference.

FIELD OF REVELATION

The present invention relates to screeds for the finishing of concrete and more particularly to vibratory screeds.

BACKGROUND OF THE REVELATION

Power screeds include a blade and a vibrating mechanism to apply vibration to the blade to facilitate smoothing and leveling of a poured, viscous material such as concrete.

SUMMARY OF REVELATION

The present disclosure provides, in one aspect, a screed comprising a drive unit; a plurality of screed blades, each of the plurality of screed blades being sequentially releasably engageable with the drive unit; a power unit controller operatively coupled to the power unit; a memory operatively coupled to the power unit controller; and a blade selector operatively coupled to the drive unit controller, the drive unit controller operable to: receive a blade selection from the blade selector, the blade selection indicating a size of a particular screed blade of the plurality of screed blades; retrieve a range of operating speeds associated with sheet selection; and adjusting the operating speed of the screed to correspond to the range of operating speeds associated with blade selection.

In another aspect, the present disclosure provides a screed comprising a drive unit; a plurality of screed blades, each of the plurality of screed blades being sequentially releasably engageable with the drive unit; and a drive unit controller operatively coupled to the drive unit, the drive unit controller operable to: monitor a blade selector for a selected screed blade size; retrieve one or more operating speeds associated with the selected screed blade size; and adjust a throttle coupled to the drive unit to the one or more operating speeds associated with the selected screed blade size.

The present disclosure provides, in yet another aspect, a method of operating a vibrating screed, receiving a selected screed blade size from a blade selector; retrieving a range of operating speeds associated with the selected screed blade size; and adjusting an operating speed of the vibrating screed to correspond to the range of operating speeds associated with the selected screed blade size.

Additional features and aspects of the disclosure will become apparent upon review of the following detailed description and accompanying drawings.

character list

• 1 Figure 12 is a schematic view of a vibrating beam.
• 2 12 is a perspective view of an exciter assembly for use with the vibratory screed of FIG 1 with a second eccentric mass in a first position.
• 3 12 is an exploded view of the exciter assembly of FIG 2 .
• 4 12 is a perspective view of the exciter assembly of FIG 2 with a second eccentric mass in a second position.
• 5 12 is a perspective view of another exciter assembly for use with the vibratory screed of FIG 1 with the exciter assembly in a second mode of vibration with medium vibrations.
• 6 12 is a perspective view of the exciter assembly of FIG 5 with the exciter assembly in a first low vibration vibration mode.
• 7 12 is a perspective view of the exciter assembly of FIG 5 with the exciter arrangement in a third vibration mode with strong vibrations.
• 8th 12 is a perspective view of a first side of a first eccentric mass of the exciter assembly of FIG 5 .
• 9 12 is a perspective view of a second side of a first eccentric mass of the exciter assembly of FIG 5 .
• 10 12 is a perspective view of a vibrating screed according to another embodiment.
• 10A 12 is a side view of the vibrating screed of FIG 10 .
• 11 Figure 12 is a cross-sectional view of the vibrating beam taken along line 11-11 in 10 .
• 12 12 is an enlarged cross-sectional view of the vibrating screed taken along line 12-12 in FIG 11 .
• 12A 12 is a cross-sectional view of the vibrating beam taken along line 12A-12A in FIG 10A .
• 13 12 is a simplified block diagram of the vibrating screed of FIG 10 .
• 14A 12 is a rear perspective view of the vibrating screed of FIG 10 .
• 14B 12 is an enlarged view of the vibrating screed of FIG 14A along line 14B-14B in 14A .
• 15 12 is a perspective view of another screed member having a plug mass for use with the vibrating screed of FIG 10 contains.
• 16 12 is a schematic view of a tunable mass system within the handle of the screed of FIG 1 or 10 .
• 17 12 is an enlarged schematic view of the tunable mass system of FIG 16 along cutting line 17-17 in 16 .
• 18 12 is a front view of a first clamp assembly configured to secure a screed member to an exciter assembly in one of the vibrating screeds of FIG 1 or 10 to fix.
• 19 12 is a side view of a second clamp assembly in an engaged position, wherein the second clamp assembly secures a screed member to an exciter assembly in one of the vibrating screeds of FIG 1 or 10 fixed.
• 20 12 is a side view of the second clamp assembly of FIG 19 in a disengaged position in which the screed member can be removed from the first clamp assembly.
• 21 12 is a schematic view of a third clamp assembly configured to fix a screed member to an exciter assembly in one of the vibrating screeds of FIG 1 or 10 .
• 22 12 is a side view of the third clamp assembly of FIG 21 in a disengaged position in which the third clamp assembly secures the screed member to the exciter assembly.
• 23 12 is a side view of the third clamp assembly of FIG 21 in a disengaged position in which the screed member can be removed from the third clamp assembly.
• 24 12 is a simplified block diagram of a vibrating screed according to another embodiment.
• 25 FIG. 14 is a flowchart showing a method of operating the vibrating screed of FIG 24 represents.

Before any embodiments of the invention are explained in detail, it should be noted that the application of the present invention is not limited to the details of construction and arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments which are capable of being practiced or carried out in a variety of ways. Furthermore, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

As in 1 As shown, a vibratory screed 10 includes a screed member 14, such as a rod or blade, for smoothing and leveling a viscous material such as concrete. The screed 10 also includes an electric motor 18, a battery pack 22 (ie, a power source) for powering the motor 18, and a frame 26 on which the motor 18 and battery pack 22 are supported. The frame 26 includes a pair of handles 30, a first platform 34 on which the engine 18 and drive housing 38 are mounted, and a second platform 38 under which the screed member 14 is mounted. In some implementations, battery pack 22 and motor 18 may be embodied as an 80 volt, high capacity battery pack and motor, such as that described in U.S. patent application Ser. 16/025,491 (now U.S. Patent Application, Publication No. 2019/0006980 ), the entire contents of which are hereby incorporated by reference, disclosed an 80 volt battery pack and motor. In such a battery pack 22, the battery cells in the battery pack 22 have a nominal voltage of up to about 80V. In some embodiments, the battery pack 22 weighs up to 6lbs. In some embodiments, each of the battery cells is up to 21 mm in diameter and up to 71 mm in length. In some embodiments, battery pack 22 includes up to twenty battery cells. In some embodiments, the battery cells are connected in series. In some embodiments, the battery cells are as such operable to deliver a sustained service discharge current of between about 40 amps and about 60 amps. In some embodiments, each of the battery cells has a capacity of between about 3.0 Ah and about 5.0 Ah. And in some embodiments of the motor 18, when used with the 80 volt battery pack 22, the motor 18 is a high output motor having a power output of at least about 2760 W and a nominal outside diameter (measured at the stator) of up to about 80 mm . In alternative embodiments, the battery pack 22 may power a motor 18 having a different power output (ie, less than or greater than) 2760W. In alternative embodiments, a gasoline engine may be used instead of an electric motor and battery pack.

With further reference to 1 Vibration dampers 42 are positioned between the first and second platforms 34, 38 and the first platform 34 and the handles 30 to dampen vibrations transmitted to the operator, the motor 18 and the battery pack 22. Another vibration dampener 46 is positioned between the drive housing 38 and the first platform 34 and the drive housing 38 . A flexible drive shaft 50 transmits torque from the motor 18 to the exciter assembly 54 configured to vibrate the screed member 14 . The exciter assembly 54 includes an eccentric mass 58 coupled for rotation with the drive shaft 50 and disposed within an exciter housing 62 coupled to the screed member 14 . In response to the motor 18 rotating the drive shaft 50, the eccentric mass 58 rotates about an axis of rotation 66 defined by the drive shaft 50, causing a rotating imbalance that transmits vibration through the exciter housing 62 to the screed member 14, thereby causing causes the screed member 14 to vibrate in a direction parallel to the axis 66 .

As in the 2-4 1, one embodiment of an exciter assembly 68 usable with vibratory screed 10 and disposed within exciter housing 62 is shown in lieu of exciter assembly 54. As shown in FIG. Exciter assembly 68 includes a first eccentric mass 70 fixed to drive shaft 50 and a second eccentric mass 74 moveable along drive shaft 50, as will be described in more detail below. A spring 78 is disposed on the drive shaft 50 and seats on the first eccentric mass 70 to bias the second eccentric mass 74 away from the first eccentric mass 70 . The drive shaft 50 includes an outer helical groove 82, the second eccentric mass 74 includes an inner helical groove 86, and a ball 90 is disposed in and between the outer and inner helical grooves 82,86. A shift collar 94 is disposed on the drive shaft 50 adjacent the second eccentric mass 74 on an opposite side of the second eccentric mass 74 from the first eccentric mass 70 . A first bearing 98 rotatably supports the input shaft 50 below the first eccentric mass 74 and a second bearing 102 rotatably supports the input shaft 50 above the shift sleeve 94.

In operation of the exciter assembly 68 of 2-4 the exciter assembly 68, in its default state, is in a first low-vibration mode indicated in 2 is shown. In the low vibration mode of exciter assembly 68, spring 78 biases second eccentric mass 74 up against shift sleeve 94 to a first position in which second eccentric mass 74 is aligned 180 degrees from first eccentric mass 70 about input shaft 50 , before. In particular, the angular position of the second eccentric mass 74 about the drive shaft 50 is determined by the position of the ball 90 in the internal helical groove 86 . When the motor 18 is activated while the exciter assembly 68 is in the first low vibration mode, the first and second eccentric masses 70, 74 rotate with the drive shaft 50, creating vibrations that are transmitted through the exciter housing 62 to the screed member 14 be transmitted. However, because the first and second eccentric masses 70, 74 are 180 degrees from each other about the drive shaft 50, the first and second eccentric masses 70, 74 act as a counterbalance with respect to one another, thereby reducing the rotational imbalance of the drive shaft 50 and hence the amplitude of the Exciter assembly 68 vibrations generated is reduced.

When the operator desires to increase the amount of vibration transmitted to the screed member 14, the operator operates a mode selector 100, such as a knob or slide actuator, on the outside of the exciter housing 62. The mode selector 100 is accessible via a switch pin 104 positioned between parallel Flanges 105 of the shift sleeve 94 are arranged, operatively coupled to the shift sleeve 94 . Operation of the mode selector 100 moves the shift sleeve 94 and thus the second eccentric mass 74 along the drive shaft 50 toward the first eccentric mass 70 to a second position ( 4 ) moves, which corresponds to a second mode of the exciter assembly 68 with high vibration. When the second eccentric mass 74 moves toward the drive shaft 50, the second eccentric mass 74 also rotates about the drive shaft 50 due to its angular position being determined by the position of the ball 90 in the inner helical groove 86. When the Motor 18 is activated, takes then, because the second eccentric mass 74 is closer to, or substantially rotationally aligned with, the first eccentric mass 70 on the driveshaft 50 in rotational alignment, the rotational imbalance of the driveshaft 50 increases, thereby increasing the magnitude of the vibrations generated by the exciter assembly 68 relative to the first mode of the exciter assembly 68 with low vibration.

Thereafter, when the operator desires to return the exciter assembly 68 to the first low vibration mode, the operator operates the mode selector 100 and shifts the shift collar 94 away from the first eccentric mass 70, causing the spring 78 to return the second eccentric mass 74 to the in 2 shown first position corresponding to the first mode of exciter assembly 68 with low vibration. In some embodiments, the shift collar 94 is moveable by the first mode selector 100 while the engine 18 is activated, and in other embodiments, the shift collar 94 is only moveable prior to operation and then locked in place prior to activation of the engine 18 .

As in the 5-7 1, an alternate embodiment of an exciter assembly 106 for use with the vibratory screed 10 disposed within the exciter housing 62 in lieu of the exciter assembly 54 or the exciter assembly 68 is shown. Exciter assembly 106 includes a first eccentric mass 110 fixed to drive shaft 50, a second eccentric mass 114 not fixed axially or rotationally to drive shaft 50, and a third eccentric mass 118 also not fixed axially or rotationally with respect to of the drive shaft 50, as will be described in more detail below. A first spring 122 is disposed on the drive shaft 50 and seats on the first compression ring 126 to bias the second eccentric mass 114 toward the first eccentric mass 110 . A second spring 130 is disposed on the drive shaft 50 and is seated on a second compression ring 134 to bias the third eccentric mass 118 toward the first eccentric mass 110 .

The second eccentric mass 114 has an eccentric weight portion 138 and the third eccentric mass 118 also has an eccentric weight portion 142 . A mode selector, such as a knob 146, on the outside of the exciter housing 62 includes a first arm 148 and a second arm 150 that are respectively or simultaneously engageable with the second and third eccentric masses 114, 118, as more fully hereinafter is explained.

As in the 5 and 8th As shown, the second eccentric mass 114 has a coupling member 154 configured to be received in a first recess 156 on a first surface 158 of the first eccentric mass 110 that is in a second eccentric mass 114 facing relationship . The first recess 156 is rotationally positioned on the first surface 158 and the clutch member 154 is rotationally positioned on the second eccentric mass 114 such that when the clutch member 154 is received in the first recess 156, the second eccentric mass 114 rotates therewith of the first eccentric mass 110 is interlocked with the drive shaft 50, and the eccentric weight portion 138 of the second eccentric mass 114 is disposed 180 degrees around the drive shaft 50 from the first eccentric mass 110.

As in the 5 and 9 As shown, the third eccentric mass 118 has a coupling member 162 configured to be received in a second recess 166 on a second surface 170 of the first eccentric mass 110 that is in a third eccentric mass 118 facing relationship . The second surface 170 of the first eccentric mass 110 is opposite the first surface 158. The second recess 166 is rotationally positioned on the second surface 170 and the coupling member 162 is rotationally positioned on the third eccentric mass 118 such that when the coupling member 162 is received in the second recess 166, the third eccentric mass 118 is locked to the drive shaft 50 for rotation with the first eccentric mass 110, and the eccentric weight portion 142 of the third eccentric mass 118 is seated on the first eccentric mass 110 on the drive shaft 50 rotationally aligned.

In operation of the exciter assembly 106 of 5-7 the knob 146 is in a first position ( 6 ) in which the knob 146 is rotated such that both the first and second arms 148, 150 engage only the third eccentric mass 118, thereby placing the exciter assembly 106 in a first low vibration mode. Since neither the first arm nor the second arm 148, 150 blocks the second eccentric mass 114, it is biased toward the first eccentric mass 110 by the first spring 122 such that when the coupling member 154 is received in the first recess 156, the second eccentric mass 114 is locked to drive shaft 50 for rotation with first eccentric mass 110, and eccentric weight portion 138 of second eccentric mass 114 is disposed 180 degrees about drive shaft 50 from first eccentric mass 110, as in FIG 6 shown is. Thus, when the exciter assembly 106 is operated in the first mode with low vibration, because the second eccentric mass 114 is locked for rotation with the first eccentric mass 110 on the drive shaft 50 and because the eccentric weight portion of the second eccentric mass 114 is 180 degrees from of the first eccentric mass 110 is rotationally offset, the first and second eccentric masses 110, 114 counterbalance each other as they rotate together about the driveshaft 50, thereby reducing the rotational imbalance of the driveshaft 50 and thus reducing the amount of vibration of the exciter assembly 106. When the first and second eccentric masses 110, 114 rotate together, the third eccentric mass 118 does not rotate with the drive shaft 50 because it is blocked from interconnecting with the first eccentric mass 110 by the arms 148, 150. Therefore, the third eccentric mass 118 remains stationary while the drive shaft 50 and the first and second eccentric masses 110, 114 rotate in unison.

If the operator wishes to increase the vibrations of the exciter assembly 106, the knob 146 is in a second position ( 5 ) in which the knob 146 is rotated so that the first arm 148 engages the second eccentric mass 114 and the second arm 150 engages the third eccentric mass 118, thereby placing the exciter assembly 106 in a second moderate vibration mode becomes, movable. In the second medium vibration mode, the second and third eccentric masses 114, 118 are respectively blocked from axially engaging the first eccentric mass 110 by the first and second arms 148, 150 such that neither the first nor second eccentric masses 114, 118 are interconnected for rotation with the first eccentric mass 110 or the drive shaft 50. Thus, when the exciter assembly 106 is operated in the second moderate vibration mode, because the first eccentric mass 110 is not rotationally coupled to the second eccentric mass 114, neither the second nor third eccentric masses 114, 118 are capable of acting as counterweights to each other (as in the first low-vibration mode). Thus, the rotational unbalance of the drive shaft 50 and a vibration amount of the exciter assembly 106 are increased with respect to the first low-vibration mode.

If the operator wishes to further amplify vibrations of the exciter assembly 106, the knob 146 is moved to a third position ( 7 ) in which the knob 146 is rotated such that both the first and second arms 148, 150 engage only the second eccentric mass 114, thereby placing the exciter assembly 106 in a third high vibration mode. Since neither the first arm nor the second arm 148, 150 blocks the third eccentric mass 118, the third eccentric mass 118 is biased towards the first eccentric mass 110 by the second spring 130 so that when the coupling member 162 is in the second recess 166 is received, the third eccentric mass 118 is locked for rotation with the first eccentric mass 110 on the drive shaft 50, and the eccentric weight portion 142 of the third eccentric mass 118 is rotationally aligned with the first eccentric mass 110 on the drive shaft 50, as in FIG 6 is shown. Thus, when the exciter assembly 106 is operated in the third high vibration mode, because the third eccentric mass 118 is locked for rotation with the first eccentric mass 110 on the drive shaft 50 and because the eccentric weight portion 142 of the third eccentric mass 118 is on the first eccentric mass 110 is rotationally aligned, the imbalance on drive shaft 50 is increased compared to when third eccentric mass 118 is spaced from first eccentric mass 110 and non-rotatable therewith. Thus, the rotational imbalance of the drive shaft 50 and the vibration level of the exciter assembly 106 are increased relative to the first and second modes. When the first and third eccentric masses 110, 118 rotate together, the second eccentric mass 114 does not rotate with the drive shaft 50 because it is blocked from interconnecting with the first eccentric mass 110 by the arms 148, 150. Therefore, the second eccentric mass 114 remains stationary while the drive shaft 50 and masses 110, 118 rotate in unison.

Typical vibratory screeds do not limit or allow the operator to adjust the amount of vibration applied to the screed member 14, regardless of the adjustment of the speed of the motor 18 (and thus the frequency, but not the amount, of vibration). . Even though the operator can change the level of vibration on typical vibratory screeds, such changes in level require manually removing a nut or bolt from the drive shaft to adjust the position of the eccentric mass to a desired position, which is time consuming, difficult and the exciter assembly undesirable can be exposed to the concrete.

Unlike typical vibratory screeds, the exciter assemblies 68, 106 are both located within the sealed exciter housing 62 and to change the amount of vibration applied to the screed member 14, the mode selectors 146 are simply adjusted. This allows the operator to quickly and efficiently change vibration modes for new pouring conditions in a screed operation while at the same time providing better protection for the exciter assemblies 68, 106 and thus increasing their longevity.

The 10-12 10 illustrate a screed 210 according to another embodiment. The screed 210 may have similar features to the screed 10 discussed above. Conversely, features of screed 210 may be applied to screed 10 discussed above. As in 10 As shown, a vibratory screed 210 includes a screed blade 214 for smoothing and leveling a viscous material such as concrete. The screed 210 also includes a brushless DC (BLDC) electric motor 218 in a motor housing 220, a battery pack 222 for powering the motor 218, and a housing 226 housing control electronics associated with the motor 218 (e.g., a or (a plurality of the electronic processor 308, the memory 312, the power switching network 316, and/or the memory 328) and on which the battery pack 222 is supported. The motor 218 includes a rotor 218a and a stator 218b ( 11 ). The screed 210 also includes a pair of handles 230 ( 10 ) extending from a frame 256 and grasped by a user to maneuver the screed 210 on a construction site.

The motor 218 is for driving an exciter assembly 234 which includes an exciter housing 238 ( 11 ) included, configured. The exciter housing 238 includes a pair of vanes 242 ( 10 ) which extend parallel to the plank sheet 214. Each wing 242 includes a clamp 246 ( 11 ) attached thereto for clamping to the screed blade 214 and fixing the screed blade 214 to the exciter housing 238. In some embodiments, clamp 246 may be configured as a quick release mechanism that includes, for example, an over center cam latch. As in 11 As illustrated, each of the clamps 246 includes an edge clamp 246a secured to an associated wing 242 and a compatible interface 246b integrally formed with the associated wing 242 of the exciter housing 238. FIG. Interface 246b is shaped to be compatible with various screed blades 214. The clamp 246 may be another mechanism operable to fix the plank blade 214 to the wing 242 .

As in the 10 and 10A As shown, vibration dampeners 250a (e.g., viscoelastic bushings or a spring damper assembly) are positioned between each of the wings 242 and the frame 256 to dampen vibrations transmitted to the operator, control electronics within the housing 226, and the battery pack 222. In addition, vibration dampers 250b (e.g. viscoelastic bushings or a spring damper unit) are arranged between the frame 256 and the housing 226 . In the illustrated embodiment of vibratory beam 210, four vibration dampeners 250a are cylindrical in shape and are disposed between frame 256 and exciter housing 238 in a rectangular configuration (when viewed from above). And in the illustrated embodiment of the vibrating beam 210, four vibration dampers 250b are cylindrically shaped and are provided in a rectangular arrangement (viewed in a direction perpendicular to the frame 256) between the frame 256 and the housing 226. Vibration dampeners 250a, 250b are relative to a vertical plane (coplanar with section 11-11 in 10 ) bisecting housing 226 and motor 218 are also positioned symmetrically.

As in 11 is shown, a drive shaft 260 receives torque from the motor 218 and transmits the torque through an intermediate shaft 268 and an elastomeric coupler 272 to an exciter shaft 264 of the exciter assembly 234. The exciter shaft 264 has an eccentric mass 276 and is supported in the exciter housing 268 by a first and second bearings 280, 284 are rotatably supported. A motor cap 288 is disposed on the motor housing 220 and covers the drive shaft 260 by extending over a neck 292 of the exciter housing 238 . In response to the motor 218 rotating the drive shaft 260, the eccentric mass 276 rotates, causing a rotational imbalance that transmits vibrations through the exciter housing 238 to the screed 214, causing the screed 214 to rotate in a vertical to the exciter shaft 264 direction vibrates.

As in 12 As shown, the first bearing 280 is disposed between the neck 292 of the exciter housing 238 and a retaining ring 296 seated in the exciter housing 238 . The second bearing 284 is disposed between a larger diameter portion 300 of the exciter shaft 264 and a lower shoulder 304 of the exciter housing 238 . As in 12A As shown, both the exciter housing 238 and the motor housing 220 are fixedly attached to an intermediate housing 305 by a plurality of fasteners 306 . At least one fastening element 306 fixes the exciter housing 238 to the intermediate housing 305. At least one fastening element 306 fixes the motor housing 220 to the intermediate housing 305. And the exciter housing 238 is rigidly connected to the wings 242, which in turn are rigidly connected to the plank sheet 214 via clamps 246 the are. Thus, vibrations generated by the rotating eccentric mass 276 are transmitted through the exciter housing 238 and vanes 242 without attenuation. The elastomeric coupler 272 is located within the intermediate housing 305. In the illustrated embodiment, the elastomeric coupler 272 is formed of plastic. The elastomeric coupler 272 provides linear isolation from vibrations generated by the eccentric mass 276 to prevent motor 218 damage. The illustrated elastomeric coupler 272 engages a secondary coupler 273 and the rotor 218a. Secondary coupler 273 engages elastomeric coupler 272 and intermediate shaft 268 .

13 12 is a simplified block diagram of the screed 210 according to one embodiment. In the illustrated example, the screed 210 includes an electronic processor 308, a memory 312, the battery pack 222, a power switching network 316 (which includes field effect transistors or FETs), a motor position sensor 320, and the trigger 324 (see 10 , showing the trigger 324 next to one of the handles 230). In some embodiments, electronic processor 308 is implemented as a microprocessor with a separate memory (e.g., memory 312). In other embodiments, electronic processor 308 may be implemented as a microcontroller (with memory 328 on the same chip). In other embodiments, electronic processor 308 may be implemented using multiple processors. Furthermore, the electronic processor 308 may be partially or fully implemented, for example, as a field programmable gate array (FPGA), application specific integrated circuit (ASIC), etc., and the memory 312 may not be required or may be modified accordingly. Memory 312 stores instructions executed by electronic processor 308 to perform functions of screed 210 described herein. Memory 312 includes read-only memory (ROM), random access memory (RAM), other non-transitory computer-readable media, or a combination thereof.

The power switching network 316 allows the electronic processor 308 to control the operation of the engine 218 . When the trigger 324 is pressed, electrical power is generally supplied to the motor 218 from the battery pack 222 via the power switching network 316 . When the trigger 324 is not depressed, the motor 218 is generally not supplied with electrical power from the battery pack 222 . In some embodiments, the extent to which the trigger 324 is depressed is related to, or is equal to, a desired speed of the motor 218 (ie, speed control). In other embodiments, the extent to which the trigger 324 is depressed is related or corresponds to a desired speed (ie, speed control or "direct drive").

In response to electronic processor 308 receiving an energize request signal from trigger 324 , electronic processor 308 activates power switching network 316 to energize motor 218 . Through the power switching network 316, the electronic processor 308 controls the amount of current available to the motor 218, thereby controlling the speed and torque output of the motor 218. The power switching network 316 includes a plurality of FETs, such as a six-FET bridge that uses pulse width modulation (PWM -) receives signals from the 308 electronic processor.

Rotor position sensor 320 is coupled to electronic processor 308 . Motor position sensor 320 includes, for example, a plurality of Hall effect sensors, an incremental rotary encoder, or the like attached to motor 18 . The rotor position sensor 320 outputs motor feedback information to the electronic processor 308, such as an indication (e.g., a pulse) when a magnet of the rotor of the motor 218 rotates across the face of a Hall sensor. Based on the motor feedback information from the rotor position sensor 320, the electronic processor 308 can determine the position, speed, and acceleration of the rotor 218a. In response to the motor feedback information and the signals from the trigger 324, the electronic processor 308 transmits control signals to control the power switching network 316 to drive the motor 18. By selectively enabling and disabling the FETs of the power switching network 316, power received from the battery pack 222 is selectively cycled to the Stator windings of the motor 218 are applied to cause the rotor of the motor 18 to rotate.

In some embodiments, motor 218 is a sensorless motor that does not include Hall effect sensors. The removal of the Hall effect sensors offers the benefit of further reducing the size of the engine block. In these embodiments, the rotor position is detected based on detecting the current, back electromotive force (back EMF), and/or the like in the inactive phases of the motor 218 . In particular, instead of the Hall sensors, current sensors, voltage sensors or the like are outside the motor 18, for example in the Power switching network 316 or a current path between the power switching network 316 and the motor 218 is provided. The permanent magnets of the rotor 218a generate a back emf in the inactive phases as the rotor 218a moves past the stator phase coils. The electronic processor 308 detects the back EMF (e.g. using a voltage sensor) or the corresponding current (e.g. using a current sensor) generated in the inactive phase to position the rotor 218a to determine. Then, the motor 218 is commutated based on the position information of the rotor 218a similarly as described above. Such a sensorless motor 218 can function without Hall sensors, acting as an incremental encoder to output motor speed. Alternatively, constant power control circuitry may be used to minimize the effect on speed as the state of charge of the battery 222 decreases. Such a sensorless motor 218 may include an initialization of the rotor alignment routine performed upon starting the rotor 218a to determine the position of the rotor 218a prior to commutation.

The motor feedback information is used by the electronic processor 308 to ensure proper timing of control signals to the power switching network 316 and to provide closed loop feedback to control the speed of the motor 218 at a desired level (i.e., at a constant speed). In particular, the electronic processor 308 increases and decreases the duty cycle of the PWM signals provided to the power switching network 316 to maintain the speed of the motor 218 at a speed selected by the trigger 324 . For example, as the load on the engine 218 increases, the speed of the engine 218 may decrease. The electronic processor 308 detects the speed decrease using the rotor position sensor 320 or the back emf sensors and proportionally increases the duty cycle of the PWM signals supplied to the power switching network 316 (and thereby the electrical power supplied to the motor 218) to bring the speed back to the to increase the desired speed. Likewise, as the load on motor 218 decreases, the speed of motor 218 may increase. The electronic processor 308 detects the speed increase using the rotor position sensor 320 or the back emf sensors and proportionally reduces the duty cycle of the PWM signals supplied to the power switching network 316 (and thereby the electrical power supplied to the motor 218) to bring the speed back to the reduce the desired speed. Such operation of electronic processor 308 may be continuous during operation of screed 210 .

Under speed control, the electronic processor 308 maintains a constant duty cycle of the PWM signals (and thereby constant electrical power supplied to the motor 218) according to the trigger 324 position.

The electronic processor 308 is operable to receive the sensed position of the rotor 218a and commutate the electric motor 18 according to the sensed position. Additionally or alternatively, the electronic processor 308 may be operable to receive the sensed speed of the rotor 218a and adjust the amount of power supplied to the electric motor 218 in the manner described above so that the motor 218 is driven at a desired speed. In the illustrated embodiment, the desired speed is a speed in excess of 9000 rpm. For example, the desired speed may be 10,000 rpm. When the speed of the electric motor 218 is maintained at the desired speed, a vibration frequency of the screed blade 214 is also maintained.

It is desirable to maintain the vibration frequency of the screed blade 214 during operation of the vibrating screed 210 . When stroking the screed blade along wet concrete, it is important to vibrate the screed blade 214 at a high enough speed for proper compaction of the concrete. If the speed of the motor 218 falls below a threshold, for example 9000 rpm, the concrete may not be compacted properly. In addition, if the speed of the motor 218 increases above a threshold, for example 15,000 rpm, the concrete may not be compacted properly. Thus, the integrity and appearance of the vibrating concrete will be adversely affected if the vibration frequency falls outside a threshold range.

By sensing the speed of the rotor 218a and commutating the electric motor 218 according to the sensed speed, the motor 218 can overcome any speed variations due to changes in the state of charge of the battery pack 222 . With use of the vibratory screed 210, the battery pack 222 discharges. The electronic processor 308 is operable to receive the sensed speed of the rotor 218a from the rotor position sensor 320 or the back EMF sensors and commutation of the motor 218 independent of the state of charge of the battery pack 222 trigger.

By utilizing the electronic processor 308 and rotor position sensor 320 of the BLDC motor 218, the screed 210 has numerous advantages over other known screeds. The screed 210 can operate at a higher efficiency compared to known screeds. By commutating the motor 218 based on the sensed speed of the rotor 218a, mechanical drag and friction between components are eliminated. By commutating the motor 218 based on the sensed position of the rotor 218a, a constant phase lead can be optimized for a relatively constant load on the tool. This is not possible with DC brush electric motors. In DC brush electric motors, brushes wear out and the phase lead changes with brush geometry. Thus, efficiency remains high because the phase lead of the brushless DC motor 218 is optimized and does not change throughout use.

The 14A and 14B 12 illustrate a throttle assembly between the trigger 324 and the electronic processor 308. As will be explained in more detail below, when operated by a screed operator, the throttle assembly provides an input signal to the electronic processor 308 that corresponds to a throttle input provided to a trigger 324. FIG. As in 14B As shown, the choke assembly includes a conduit connector 332 (which includes male and female electrical plugs) positioned in a connector housing 336 . The connector housing 336 surrounds the connector 332 to prevent ingress of unwanted material (ie, debris such as water, concrete, moisture, dust, dirt, etc.) from contacting the connector 332. In some embodiments, the connector housing 336 is configured as an IP (ie, Ingress Protection) rated connector housing 336 that prevents water, concrete, or other materials from entering the housing 336 and contacting the connector 332 . The connector housing 336 may be removably fixed to the motor housing 220 by one or more fasteners 338 (e.g., screws).

The choke assembly also includes an outer wiring harness 340 extending between trigger 324 and connector 332 . Outer wire harness 340 has a first end 340a coupled to trigger 324 and an opposite second end 340b coupled to connector 332, with second end 340b terminating in one of the male and female plugs of the conduit connector 332 completes. The second end 340b of the outer wire harness 340 is positioned within the connector housing 336 with a portion of the outer wire harness 340 protruding from the connector housing 336 . Optionally, a portion of outer wire harness 340 extends through handle 230.

The choke assembly further includes an internal wiring harness 344 having a first end 344a terminating in the other of the male or female plug of the conduit connector 332 . The first end 344a of the inner wire harness 344 is also positioned within the connector housing 336 . In some embodiments, inner wire harness 344 protrudes from connector housing 336 en route to electronic processor 308 . In other embodiments, the entirety of the inner wire harness 344 is positioned in a combination of the connector housing 336 and the motor housing 220 . The inner wire harness 344 includes an opposite second end 344b that is coupled to the electronic processor 308 (via a circuit board and one or more electrical connectors).

Both the second end 340b of the outer wire harness 340 and the first end 344a of the inner wire harness 344 reside within the connector housing 336 when the connector housing 336 is fixed to the motor housing 220 . In other words, the outer wire harness 340 is electrically connected to the inner wire harness 344 through the connector 332 in the connector housing 336 . Thus, ingress of unwanted material (e.g., water, concrete, moisture, dust, dirt, etc.) is prevented from contacting the electrical connections in connector 332 .

Providing the line connector 332 surrounded by a connector housing 336 on the outside of the screed 210 provides protection and promotes easy access to the line connector 332 for maintenance. The connector housing 336 can be removed from the motor housing 220 by removing the fastener 338 and then lifting the connector housing 336 away from the motor housing 220 . This exposes the wire connector 332 for service, allowing the first end 344a of the inner wire harness 344 to be disconnected from the second end 340b of the outer wire harness. Thus, independently of the housing 226 which houses the control electronics associated with the motor 218, the handle 230, outer wiring harness 340 and trigger 324 can be removed together as a unit from the motor housing 220 for servicing.

In some embodiments, the screed member 14 may include a plug mass 356 for changing the natural frequency of the screed member 14 (when absent of connector ground 356). As in 15 As shown, the connector ground 356 is located adjacent one end 14a of the plank member 14. However, in other embodiments, the connector ground 356 may be located elsewhere along the length of the plank member 14. In some embodiments, connector mass 356 is formed from a plastic, rubber, or metal material. In some embodiments, plug mass 356 is a molded insert that can be installed into at least one end 14a of plank member 14 . In some embodiments, plug ground 356 is installed at both ends 14a of plank member 14 . In some embodiments, the plug mass 356 can be removed from the plank member 14 and repositioned elsewhere along the length of the plank member 14 . Further, plug masses 356 made of a first material may be removed from the screed member 14 and replaced with plug masses 356 made of a second material different from the first material. In other embodiments, the plug mass 356 may be fixed to the plank member 14 .

The screed member 14 itself may define a natural screed frequency based on the geometry and material properties of the screed member 14 . In some embodiments, plank member 14 may be made from extruded aluminum or magnesium. In some embodiments, the plank member 14 may be made from a single piece of metal. In some embodiments, the plank member 14 (by being hollow) may have a wall thickness. The material properties and geometry of the screed member 14 contribute to the screed member 14 having the natural screed vibration frequency.

Depending on the material and geometry of the screed member 14, as well as the operation of the motor 218, the natural screed frequency may be close to the frequency of vibration emitted by the exciter assembly 54, 234 (i.e., the exciter frequency). The excitation frequency may generally correspond to a speed of the motor 218 (e.g., 9000 rpm [150 Hz]) and/or 15,000 rpm [250 Hz]). If the natural screed frequency and the excitation frequency get too close together, unwanted resonance could result, in some cases damaging the motor 218 and/or other components of the vibrating screed 210 .

The inclusion of the plug mass 356 in the screed member 14 can adjust the screed natural frequency of the screed member 14 and plug mass 356 combination to be unequal the excitation frequency to avoid resonance and any resulting damage to the motor 218 . In other words, the natural frequency of the combination of screed member 14 and plug mass 356 is further from the frequency of vibration emitted by the exciter assembly 54, 234 than the natural frequency of screed member 14 alone.

The 16 and 17 12 illustrate a tunable mass system 358 coupled to the handle 230. The tunable mass system 358 may include an end cap 360, a spring member 364, and a tuned mass 368. FIG. The end cap 360 may be provided adjacent an end 230a of the handle 230 . In the illustrated embodiment, end cap 360 may extend to end 230a. However, end cap 360 may be otherwise provided adjacent end 230a. Spring member 364 may have a first end 364a coupled to end cap 360 . Spring member 364 may have an opposite second end 364b coupled to tuned mass 368 . As best in 17 1, in the illustrated embodiment, spring member 364 may be a coil spring. However, in other embodiments, the spring member 364 may be another elastically deformable member. In some embodiments, spring member 364 may be made of an elastomer or spring steel, for example. The end cap 360 can be aligned along a cap axis 362 . In some embodiments, cap axis 362 may extend through the center of end cap 360 . In some embodiments, cap axis 362 is coaxial with handle 302. End cap 360 may be sufficiently fixed to handle 230 so as not to deflect relative to handle 230. FIG. The spring member 364 may be sufficiently elastically deformable such that the tuned mass 368 may become misaligned with the cap axis 362 as the handle 230 vibrates. The tuned mass 368 can attenuate vibrations generated by the vibrating beam 210 . The tuned mass 368 can move within the grip 230 to substantially attenuate vibration of the handlebars 230 .

A user operating screed 210 may hold handle 230 adjacent to balanced mass system 358 . This can limit the amount of vibration transmitted through the handle 230 to the user during operation.

The 18 until 23 12 illustrate quick release clamp assemblies 372, 376, 380 for selectively retaining screed member 14, 214 to exciter housing 238. Each clamp assembly 372, 376, 380 is movable between a disengaged position 372a, 376a, 380a, respectively, and an engaged position 372b, 376b, 380b . Each assembly may include an edge clamp 384 connected by a linkage mechanism 392 with a latch member 388 may be coupled. Thus, the latch member 388 can be pivoted along an arrow A1 between the respective disengaged position 372a, 376a, 380a and the respective engaged position 372b, 376b, 380b. Each clamp assembly 372, 376, 380 may be configured while in the engaged position 372b, 376b, 380b to fix the screed member 14 to the exciter housing 238 (and thus the exciter assembly 234) to reduce vibrations generated by the exciter assembly 234 to transfer to the screed member 14. In the engaged position 372b, 376b, 380b of each clamp assembly 372, 376, 380, the edge clamp 384 may be wedged to the plank member 14. In the disengaged position 372a, 376a, 380a of each clamp assembly 372, 376, 380, the edge clamp 384 releases the screed member 14 from the exciter housing 238, allowing the screed member 14 to be removed and replaced with another screed member 14.

18 14 depicts both the disengaged position 372a and the engaged position 372b of the clamp assembly 372. The two-armed linkage 396 may include a first rod 396a and a second rod 396b. The first rod 396a can be coupled to the edge clamp 384 . The second rod 396b may have a first end coupled to the first rod 396a and an opposite second end coupled to the latch member 388 . In some embodiments, at least one of the first bar 396a and the second bar 396b may be adjustable in length. In the illustrated embodiment, the first rod 396a may be adjustable in length and the first rod 396a may be provided with a spring 400. When the latch member 388 is rotated along arrow A1 to the engaged position 372b, the spring 400 may be compressed to translate the edge clamp 384 toward the plank member 14. Upon full rotation of the latch member 388 to the engaged position 372b, the edge clamp 384 may be wedged to the plank member 14. In the engaged position 372b , the spring 400 may bias the edge clamp 384 such that the screed member 14 may be fixed to the exciter housing 238 .

The 19 and 20 12 depict the disengaged position 376a and the engaged position 376b of the clamp assembly 376, respectively. The connecting rod 400 may have a first end coupled to the first edge clamp 384 and an opposite second end coupled to the toggle lever 396 . Latch 388 may be rotatable along arrow A1 to pivot toggle 396 . Upon pivoting of toggle 396, connecting rod 400 may be translated along arrow A2 to extend and retract edge clamp 384 between disengaged position 376a and engaged position 376b. In some embodiments, the connecting rod 400 may have an adjustable length to allow a user to adjust the preload on the plank member 14 when in the engaged position 376b. In embodiments having an adjustable length connecting rod 400, the adjustable connecting rod 400 may alleviate the need to replace the clamp assembly 376 and/or the plank member 14 due to interface wear by providing means for adjusting the preload.

The 21-23 illustrate the clamp assembly 380. The clamp assembly 380 is shown in FIGS 21 and 22 shown in the engaged position 380a. The clamp assembly 380 is shown in FIGS 21 and 23 shown in the disengaged position 380b. As in 21 As shown, the vibrating screed 210 may include two clamp assemblies 380 spaced along the length of the screed member 14 . In the clamp assembly 380, the linkage mechanism 392 may be provided as a cam 404 at one end of the latch member 388. As shown in FIG. In the engaged position 380a, contact between the cam 404 and the edge clamp 384 provides adequate contact force to fix the screed member 14 to the exciter housing 238. The contact area between the cam 404 and the edge clamp 384 provides a large mechanical advantage. In some embodiments, edge clamp 384 may be spring-loaded to allow edge clamp 384 to open automatically when clamp assembly 380 is in disengaged position 380b. In transitioning between the engaged position 380a and the disengaged position 380b, the latch 388 may pivot along arrow A1 and the cam 404 may cause the edge clamp 384 to pivot along arrow A3.

With reference to 24 A block diagram of another vibrating beam 500 is shown. In addition to the in 24 shown, the vibrating beam 500 can have one or more of the 13 include features or components shown. As in 24 As shown, the screed 500 includes a power unit controller 502. The power unit controller 502 may be a central processing unit (CPU) or a microprocessor. Furthermore, the drive unit controller 502 can a be an engine controller or an engine controller. The drive unit controller 502 is operatively connected to a drive unit 504 , an accumulator 506 , a blade selector 508 and a throttle 510 . In a particular embodiment, drive unit 504 includes an electric motor that receives power from a direct current (DC) source, e.g. a battery, or from an alternating current (AC) source, and an exciter assembly (e.g., exciter assembly 234) that receives torque from the engine to impart vibration, as described above. In another embodiment, power unit 504 may include an internal combustion engine that derives power from burning a fossil fuel, such as gasoline, diesel fuel, propane, or natural gas.

As in 24 As shown, a trigger 512 is operatively connected to the choke 510 . A first screed blade 514a, a second screed blade 514b, or an nth screed blade 514c is operatively connected to the drive unit 504. It should be understood that each plank blade 514a, 514b, 514c is releasably engaged to the drive unit 504 and only a single plank blade 514a, 514b, 514c can be engaged to the drive unit 504 at a time. 24 12 also shows that the screed 500 includes a first speed sensor 516 associated with the power unit 504 to detect the speed of the power unit 504. FIG. In some embodiments, the first speed sensor 516 may be integrated with the drive unit 504 and may be configured, for example, as a Hall effect sensor or sensory array for detecting a speed of an electric motor. Furthermore, in some embodiments, the vibratory screed 500 may include a second speed sensor 518 (e.g., a vibration transducer or accelerometer) adjacent the screed blade 514a, 514b, 514c to measure the oscillation (reciprocating) speed or frequency of the screed blade 514a, 514b, 514c to be detected.

The blade sensor 508 allows a user to select a size of the screed blade 514a, 514b, 514c that the drive unit 504 engages. Depending on the actual application, screed blades 514a, 514b, 514c, having different sizes (e.g., lengths and weights), may releasably engage drive unit 504. For example, paving a concrete sidewalk may require a much smaller sheet of planks 514a, 514b, 514c than paving a concrete foundation for a six car garage. Thus, the plank sheets 514a, 514b, 514c can range in length from four feet to sixteen feet (4ft - 16ft). After engaging a particular plank blade 514a, 514b, 514c with the drive unit 504, the user can use the blade selector 508 to select a size corresponding to the plank blade 514a, 514b, 514c that the drive unit 504 is engaged with. As described in detail below, the size of the screed blade 514a, 514b, 514c determines the operating speed range of the drive unit 504.

As described in more detail below, a user selects a blade size associated with the screed blade 514a, 514b, 514c coupled to the drive unit 504 during operation. Based on the blade size, the power unit controller 502 adjusts the throttle 510 to operate in a speed range associated with the selected size of the screed blade 514a, 514b, 514c. The speed range for each screed blade 514a, 514b, 514c is based on the natural frequency of the screed blade 514a, 514b, 514c. The optimal vibration of the screed blade 514a, 514b, 514c is determined by the closeness of the frequency of the vibrations emitted by the drive unit 504 to the natural frequency of the screed blade 514a, 514b, 514c. When the drive unit 504 excites the screed blade 514a, 514b, 514c to its natural frequency, the drive unit 504 is operated at a "critical speed" associated with the screed blades 514a, 514b, 514c. However, operating the screed blade 514a, 514b, 514c at its natural frequency can cause the performance of the vibrating screed 500 to degrade. This prevents each plank sheet 514a, 514b, 514c from being excited to its natural frequency.

The natural frequency of each plank sheet 514a, 514b, 514c depends at least in part on the stiffness of the plank sheet 514a, 514b, 514c and the mass of the plank sheet 514a, 514b, 514c. And the stiffness of the plank sheet 514a, 514b, 514c depends at least in part on the length of the plank sheet 514a, 514b, 514c, the cross-sectional area (moment of inertia) of the plank sheet 514a, 514b, 514c, and the material from which the plank sheet 514a, 514b, 514c manufactured , from. And the stiffness of the plank sheet 514a, 514b, 514c depends at least in part on the length of the plank sheet 514a, 514b, 514c, the volume of the plank sheet 514a, 514b, 514c, and the material from which the plank sheet 514a, 514b, 514c is made .

The desired or allowable excitation frequencies associated with each particular screed blade 514a, 514b, 514c may be stored in memory 506. When the user pulls or otherwise squeezes the trigger 512, the throttle 510 is adjusted to cause the drive unit 504 to operate within the range of speeds associated with the selected screed blade 514a, 514b, 514c. which avoid the natural frequencies of the respective plank sheets 514a, 514b, 514c. During operation of the power unit 504, the power unit controller 502 uses input from the first speed sensor 516 to sense the speed of the power unit 504 and the optional second sensor 518 to sense the vibration frequency of the screed blade 514a, 514b, 514c. Based on these inputs, the drive unit controller 502 modifies the speed of the drive unit 504 to ensure that the drive unit 504 is not at or near the critical speeds associated with the natural frequencies of the screed blades 514a, 514b, 514c that are affecting the performance of the vibrating screed 500 could affect works.

25 FIG. 14 is a flow chart depicting a method, generally designated 600, of operating a vibratory screed. Beginning at block 602, method 600 monitors a leaf selector after power-up. At decision 604, method 600 determines whether a new sheet size is selected. If a new blade size is selected, method 600 proceeds to block 606 and method 600 retrieves one or more operating speeds associated with the selected screed blade size. Further, at block 608, the method 600 sets the throttle to the operating speeds, ie operating range, for the selected screed blade size. Thereafter, method 600 continues to decision 610 . Returning to decision 604, if the method 600 determines that a new screed blade size is not selected, the method 600 proceeds to block 612. At block 612, the method 600 maintains the current operating speeds associated with the current screed blade. Then the method 600 moves to decision 610 .

At decision 610, method 600 determines whether trigger 512 is pressed. If the trigger is not depressed or otherwise actuated, the method 600 returns to block 602 and continues as described herein. On the other hand, if the trigger 512 is pressed, the method 600 proceeds to block 614 where the method 600 operates the drive unit 504 based on the screed blade size. Next, at block 616, the method 600 monitors the speed of the drive unit 504, the frequency of vibration of the blade, or a combination thereof. Proceeding to decision 618, the method 600 determines whether the speed of the power unit 504 is near a critical speed, i. H. approaches the natural frequency of the plank sheet 514a, 514b, 514c. If so, the method 600 proceeds to block 620 and adjusts the operating range to avoid the critical speed. Thereafter, the method 600 proceeds to decision 622. Returning to decision 618 , if the speed of the screed blade is not approaching a critical speed, the method 600 proceeds to decision 622 .

At decision 622, method 600 determines whether trigger 512 is enabled. If not, the method 600 returns to block 616 and continues to monitor the speed of the drive unit 504 and blade before proceeding as described herein. Otherwise, at decision 622, if the trigger is released, the method 600 proceeds to decision 624. At decision 624, method 600 determines whether screed 500 is off. If the screed 500 is off, the method 600 ends. On the other hand, if the screed 500 remains on, the method 600 may return to block 602 and the method 600 may continue as described herein.

Unlike conventional vibratory beams which only allow a limited amount of user input to the vibrations applied to the concrete, the system and method described above enable a user to adjust the level of vibration applied to the concrete. This is accomplished by enabling the user to select a particular screed with associated speeds via the selected sheet. This allows the user much more control over the concrete pouring process by allowing the user to select a specific screed blade length and allowing the system, e.g. the vibrating screed, is allowed to adjust the speed of the vibrating screed based on the selected screed blade length. Thus, during operation of the vibrating screed 500, a predetermined speed range unique to each selectable screed blade is provided. The power unit controller 502 uses the sensors 516, 518 to avoid critical speeds that negatively impact the user experience. These adverse experiences may include increased vibration from the vibrating screed 500, poor surface condition of the concrete on which the vibrating screed 500 is used, and increased power consumption for the drive unit 504 of the vibrating screed 500.

Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.

Various features of the invention are set out in the following claims.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US63300418B[0001]
• US 16/025491 [0009]
• US2019/0006980 [0009]

Claims (20)

Vibrating beam, comprising: a drive unit, a plurality of screed blades, each of the plurality of screed blades being sequentially releasably engaged to the drive unit; a power unit controller operatively coupled to the power unit; a memory operatively coupled to the power unit controller; and a sheet selector operatively coupled to the drive unit controller, the drive unit controller operable to: receive a blade selection from the blade selector, the blade selection indicating a size of a particular plank blade of the plurality of plank blades; retrieve a range of operating speeds associated with sheet selection; and adjust the operating speed of the screed to match the range of operating speeds associated with blade selection. Rüttelbohle after claim 1 , further comprising a plurality of allowable excitation frequencies stored in memory and associated with each of the plurality of screed blades. Rüttelbohle after claim 1 , further comprising a first speed sensor for detecting a speed of the drive unit. Rüttelbohle after claim 3 , further comprising a second speed sensor for detecting the frequency of vibration of the selected screed blade engaged with the drive unit. Rüttelbohle after claim 4 , wherein the power unit controller is further operable to receive inputs from the first speed sensor and the second speed sensor. Rüttelbohle after claim 1 wherein the drive unit controller is further operable to determine a frequency of vibration of the screed blade with the input received from a sensor. Rüttelbohle after claim 6 wherein the drive unit controller is further operable to modify a speed of the drive unit to prevent the drive unit from operating at a critical speed associated with a natural frequency of the selected screed blade. Vibrating beam, comprising: a drive unit, a plurality of screed blades, each of the plurality of screed blades being sequentially releasably engaged to the drive unit; a drive unit controller operatively coupled to the drive unit, the drive unit controller operable to: monitor a blade selector for a selected screed blade size; retrieve one or more operating speeds associated with the selected screed blade size; and adjust a throttle coupled to the drive unit to the one or more operating speeds associated with the selected screed blade size. Rüttelbohle after claim 8 , further comprising a trigger configured to selectively activate the drive unit, wherein the drive unit controller is further operable to determine when the trigger is pressed. Rüttelbohle after claim 9 wherein the drive unit controller is further operable to operate the drive unit based on the selected screed blade size when the trigger is pressed. Rüttelbohle after claim 10 wherein the power unit controller is further operable to monitor a speed of the power unit. Rüttelbohle after claim 11 wherein the drive unit controller is further operable to determine when the speed of the drive unit is approaching a critical speed associated with a natural frequency of the selected screed blade engaged with the drive unit. Rüttelbohle after claim 12 wherein the power unit controller is further operable to adjust the speed of the power unit to avoid the critical speed. A method of operating a vibrating beam, the method comprising: receiving a selected screed blade size from a blade selector; retrieving a range of operating speeds associated with the selected screed blade size; and adjusting an operating speed of the vibrating screed to correspond to the range of operating speeds associated with the selected screed blade size. procedure after Claim 14 , where the selected screed sheet size indicates a size of a particular screed sheet. procedure after Claim 14 , further comprising determining when a trigger of the screed is pressed. procedure after Claim 16 , further comprising operating a drive unit of the vibrating screed based on the selected screed blade size when the trigger is pressed. procedure after Claim 17 , further comprising monitoring a speed of the drive unit. procedure after Claim 18 , further comprising determining when the speed of the drive unit approaches a critical speed associated with a natural frequency of the selected screed blade engaged with the drive unit. procedure after claim 19 , further comprising adjusting the speed of the drive unit to avoid the critical speed.

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